Earthmoving equipment and construction machines such as, for example, hydraulic excavators and track-type tractors, are used to perform a variety of tasks, typically in rugged environments. In order to enable machine movement, one or more track mechanisms may be provided on such machines. Conventional track mechanisms may include a drive sprocket and one or more idlers to support and enable movement of a ground engaging track about the drive sprocket and idler(s). A track idler may rotate about an axis, and may include a rim portion that engages a plurality of track link members that are interconnected by spaced track pins. Some idlers, for example center tread idlers, engage bushings extending between the laterally spaced links of a track mechanism. The drive sprocket, in combination with the engagement between the idler rim and the track bushing, provides the force that moves the machine. However, contact between the idler rim and the track bushings generate noise and vibrations that are detrimental to both the machine and its operator.
To help dampen the vibration and noise created by metal-on-metal contact in track assemblies and idler wheels, isolation devices, such as, for example, rubber inserts, have been used. U.S. Pat. No. 3,127,211 (the '211 patent) issued to Kordes et al. on Mar. 31, 1964, discloses a wheel assembly that employs an elastic member placed between a rim and a wheel body. In particular, the '211 patent describes a rail vehicle wheel with an elastically supported rim in which two annular elastic inserts may be provided between the wheel body and the rim.
Although the rail vehicle wheel of the '211 patent may provide some damping of vibration and noise by employing elastic inserts, the arrangement in the '211 patent may have limitations. For example, forces exerted by the rim on the elastic inserts may be so great as to repeatedly compress the elastic inserts beyond their elastic limit. This may lead to early failure of the elastic inserts. Also, the arrangement of the rim relative to the elastic inserts and the wheel body may cause the elastic inserts of the '211 patent to potentially experience both tension and compression and incur destructive shear forces under side loading. In addition, assembly of the wheel of the '211 patent may be problematic. The shape and relationship of components in the '211 patent may render it difficult to property seat both annular elastic inserts during assembly.